This invention relates to patch antennas and more particularly to directional patch antennas wherein multiple patch radiators are used to control the direction of a beam of radio frequency (RF) energy from the antenna.
In missile applications, antennas are often required to be mounted conformally with the generally cylindrical shape of a missile. Antennas which adapt easily to conformal mounting usually produce a beam of RF energy having a main lobe directed normally (or broadside to) the missile. In some applications, the required direction of the main lobe of the beam of RF energy is in a direction along an axis of the missile. To provide the latter, known patch antennas either include elements which are parasitically fed or corporate feeds to provide the RF energy to each patch element. A corporate feed includes components that occupy critical area internal to the missile. The mass and volume of all components within the missile are critical to the performance of the missile and any decrease in the size and number of components is highly desirable.